Mixing machine



F. BEKEN MIXING MACHINE 2 4 9 1 3 1 n a J Original Filed May 15, 1936 2Sheets-Sheet l INVENTOR. BY V; 4% 245 6 0.. v M.

Jan; 13, 1942. F. BEKEN MIXING MACHINE Original Filed May 15, 1956 2Sheets-Sheet 2 k ll /Z Reissueri 13, 1942 MIXING MACHINE Fritz Beken,Ilford, England Original No. 2,095,901, dated October 12, 1937,

Serial No. 79,976, May 15, 1936. Application for reissue February 21,1939, Serial No. 257,766. In Great Britain July 24, 1935 7 Claim.

This invention relates to mixing machines, and has for its object theprovision of an improved machine which will intimately mix variousmaterials in a shorter time than has hitherto been possible, or which,if the mixing process is not materially hastened, will produce a moreperfect mixture than is obtained by other machines of the type employingrotating beaters, paddles or agitators to which the present inventionrelates.

The improved machine hereinafter described is particularly adapted formixing plastic materials but may be employed also for mixing granular orpowdered materials or even in mixing processes in which a liquid, suchas a chemical solution for example, is added to the material undertreatment.

The invention is characterized by various featureswhich will bedescribed more fully hereinafter. Referring to the same briefly and ingeneral, at this point, paddles on parallel shafts are caused to coact,these rotating in opposite directions at different speeds, so thatblades of one paddle recurrently overtake blades of the coacting moreslowly moving paddle. The angular setting of the blades onthe twoshafts, in relation to each other, their shapes, and relative speeds,and the spacing of the shafts, are calculated to enable desired eifectsto be obtained, in the squeezing and drawing out of the material betweenco-acting paddles, as is more fully described hereafter.

Preferably, also, a plurality of paddles are spaced axially along eachof the shafts, each paddle on one shaft coacting with a paddle on theother shaft, coacting paddles being alined with each other in a plane atright angles to the axis of rotation. The blades of the paddlespreferably are arranged to cause the material to move axially of theshafts, in addition to its rotating movement. This may be accomplishedby setting the blades, as to their lateral dimensions, at angles to theaxes of the shafts. Preferably also. with a plurality of paddles spacedalong each shaft, the blades of one or more paddies on one shaft are setat an angular advance, or retardation, each in its plane of rotation;with respect to the blades of a preceding paddle on that shaft. whilethe blades of the coacting paddles on the other shaft have suitableangular relations, in each case, to the blades of the coacting paddle onthe first shaft, enabling the same cycle of operations to take placebetween.

each coacting pair of paddles,'but with a diflerent timing as betweensome of the coacting pairs. In the machine illustrated, one paddle shaftis adapted to rotate at twice the speed of the other paddle shaft.

The nature of the invention will be more clearly appreciated byreference to the accompanying drawings, illustrating by way of exampleone form of mixing machine embodying the invention, similar referencecharacters referring to like parts in the figures:

Figure 1 being a sectional elevation;

Figure 2 a plan view; and

Figures 3-11, inclusive, are a series of diagrams showing relativepositions of coacting paddles in the operation of the machine.

Referring tov the drawings, it will be seen that on the main frames orstandards a of the machine are mounted the main mixture driving shaft band the two secondary parallel horizontal driven shafts c and d thatrespectively carry paddles or heaters each havin two blades which arerotated in the interior of the stationary mixing casing g that containsthe material under treatment.

With the use of a plurality of pairs of coacting paddles as shown, theangular relationship of the blades of each paddle in reference to theblades of its coacting paddle on the other shaft will be such as toproduce the same cycle of operations by each pair of coacting paddles.As to the paddles mounted on the same shaft, however, there may be anangular advance or setting back of the blades of one or more paddleswith respect to the blades of another paddle or paddles on the sameshaft. Thus, in the construction shown in Fig. 2, the blades E21 of twoof the paddles on shaft c are so set that they are about at right anglesto the remaining blades on the shaft. Because of the preferred spiralarrangement of the blades, which is presently to be described, it shouldbe said, more strictly speaking, that the blades E21 and En of the twopaddles are moved back with respect to the blades E11 and E1: of theremaining two. E paddles on the shaft so that the blades Em and E22 ofthe third paddle from the right in Fig. 2 are, at their right hand edgeportion, set back about ninety degrees with respect to the blades E11and E1: of the first E paddle at their right hand edge portion, andsimilarly the blades E21 and E2: of the fourth paddle are, at theirright hand edge portion, set back about ninety degrees with respect tothe blades E11 and E1: of the second paddle at their right hand edgeportion. Therefore, as to either of the pairs of blades-E21 and E22, ata plane at right angles to the shaft 0 at any distance from the righthand edge of such blades, they are set backaboutninetydegreeswithmecttothe corresponding pair of blades E11 and R1: at a similar planeatthesamsdistance fromthel'lsbt hand edgeofsuchblades. Also.thebladesofthefourpaddlesonshaftdareallsetatangles' m on one end of the paddleshaft 11. On the other end of the shaft 11 is mounted a spur wheel athat meshes with a larger spur wheel mounted on the other paddle shaft0. The gear wheels nandoare,asshown,intheratioofonetotwo. in size, sothat the paddle shaft 11 rotates at twice the speed of the paddle shaftc.

Inch paddle consists of a hub p with a pair of blades extendingoppositely therefrom, in alinement with each other, that is, two bladesone hundred and'eighty degrees apart. with their center lines in thesame plane; or it may consist of a longer hub with two or more bladesaxially separated from each other on each hub.

In the arrangement illustrated, the paddles and their respective bladesare identified as follows. As shown in Fig. 2, there are four paddles onthe shaft 4. For convenience, they are considered in two groups. Theiroppositely extending blades are identified as F11 and F1: for those onthe right (Fig.2) and 1'51 and F11 respectively for those on the left(Fig. 2)

There are four paddles on the shaft c which are adapted to coact withthe four paddles on shaft it. They will be also considered in groups oftwo. Their respective oppositely extending blades are identified by thereference characters E11 and E1: as to those at the right (Fig. 2) andE11 and En for those at the left (Fig. 2).

Each paddle on oneshaft co-operates with a similar paddle. alinedtherewith, on the other shaft, as is indicated above, such a pair ofcooperating paddls comprising, in effect, an operating unit. For themost efllcient operation a plurality of such units are employed. Asshown in the drawings, four such paddles are mounted on shaft 1,co-operatlng with similar paddles on shaft 0.

The shafts c and d are spaced apart a suitable distance so that theouter edges of the blades on one shaft will wipe over the hubs of thealined paddles on the other shaft, in their respective revolutions, asshown. Also, the blades, for the most eiiicient operation, are of curvedformation, each blade preferably having a concavely-curved forward faceq, and a convexly-curved rear face,

' 1-, which is Joined to the hub by the concavely curved fillet 1- Theblades also are shown as inclined at an,

blades enables the outer edges of the blades 7 of the interior of thecasing. with this arrangement the concavely-curved forward face of eachblade will carrymaterial under treatment up, adjacent to the side of thecasing, and over the top of its shaft, this material then being forceddownwardly by the revolving blade in the space between the two shafts.

The blades of each paddle areset at such angles in their planes ofrotation. in relation to the angular setting of the blades of thecorresponding paddle on the other shaft, as to enable the said blades tocoact'in the mixing process without collision or interference.Considering a pair of coacting paddles and their blades E11 and F11, orE1: and F11. the blades coact in the course of their rotation inopposite directions. That is to say, as the blades of one shaft approachthe blades of the other they provide opposed surfaces between which thematerial is pressed, and withv the method of driving described theinterengagement of the paddles ensures what may be termed apush-and-pull" action on the material under treatment.

During one phase of the revolution the more rapidly moving blades F11and F1: overtake the blades E11 and E11, that move at half the speed ofthe blades F11 and F11, and the material is therefore pushed or squeezedbetween the two sets of blades, and so is thoroughly kneaded anddistributed throughout the mass. During the next phase of the revolutionthe blades F11 and F11 have passed the blades E11 and E1: and so exert apulling action on the material, drawing it out or stretching it betweenthose slow moving and the fast moving blades. This, in con- Junctionwith the kneading action of the former phase, givm very effectiveresults, more especially in the mixing of materials of a plastic nature.The above descriptionapplies equally to the action between all opposed,that is coacting, blades.

The operation, referred to generally above, will be made clearer by amore detailed description, with particular reference to the series ofdiagrams, Figs. 3-11, inclusive. In these diagrams relative successivepositions are plotted of a pair of blades E11 and E1: on the slowershaft 0 coacting with a pair of blades F11 and F1: on the faster shaft:1, it being understood that in the construction illustrated the shaft11 makes one revolution while the shaft c makes one-half a revolution,and the blades E11 and E1: are the two blades of one paddle which coactwith the two blades F11 and P1: of the opposed paddle. these blades allbeing shown in full lines-in Figs.

3-11, inclusive. The blades shown in dotted lines a on shaft 0 are theblades E11, E22 which coact with the blades F11, F11, on shaft 11, aswill be described later.

In the first position of the diagrams, as shown in Fig. 3, the blade F1:is shown extending vertically upwardsfrom the shaft 11, while the bladeE11, extending upwardly from shaft 0, inclines at a slight angle to thevertical, toward the blade F11. Starting the movement of the parts fromthe said position, the blade F1: moves downward- Lv, counter clockwise,and passes in front of blade E11, which is moving down in the clockwisedirection, at one-half of the speed of rotation of blade F11. In thesecond position, as shown in Fig. 4 in the diagrams the outer edge ofblade F11, having advanced through forty-five,

degrees, is beginning to pass within and adjacent to the concave forwardface of blade E11, and in the third position. as shown in Fig. 5, thepassage of the outer edge of blade F12 over the concave face ofblade E11has continued, with the elect of removing some material that may beadhering to this face.

With the continuance of the movement the faster blade, F12. draws awayfrom blade E11, its outer edge swinging downwardly of! the hubs ofblades E11 and E12, both blades F12 and E11 moving downwardly at thistime, in the space between the two shafts. During the separation ofthese blades, which occurs between the third and fourth positions, asshown respectively in the diagrams, Figs. and 6, the material beingtreated will be drawn .out between them.

Continuing the movement, the outer edge of blade E11 will wipe over oradjacent to the hubs of blades F11 and F12. This is the position shownin Fig. 6. The blade of F11 now passes the upper vertical position inits counter-clockwise movement, as is indicated in the fifth position,as shown in Fig. "l, and approaches the back of blade E11, these blades,as blade F11 overtakes the slower blade E11, assuming at one moment aposition in which they are almost parallel, as is indicated in the sixthposition, as shown in Fig. 8. The material will be pressed or squeezedbetween these blades, as blade F11 approaches blade E11. 1

In the continued movement, the outer edge of blade F11 passes closelyadjacent to the hub of the coacting paddle as is shown in the seventhposition, Fig. 9, and then adjacent to a portion of the convexly-curvedsurface 1' of blade E11,

with the effect of removing therefrom some material that may be adheringthereto. The blades F11 and E11 now move away from each other, theybeing now adjacent to the bottom points of their rotations, as isindicated in the eighth and ninth positions, Figs. 10 and 11,respectively, and during this separation of the blades, the materialwill be drawn out between them. The blade F12, in the ninth position,Fig. 11, has returned to the top, completing one revolution.

During the next revolution of blades F11 and F12. and half revolution ofblades E11 and E12. the movementswill be similar, the outer edge ofblade F12 passing within and adjacent to the curved front surface ofblade E12, with a subsequent drawing out of the material, after whichblade E12 passes close to the hub and adjacent to the back of blade F12,and blade F11 passes behind blade E12, squeezing the material as bladeF11 overtakes blade E12, blades F11 and F12 then separating and drawingout the material between them, thus completing what may be termed thecycle of operation of these two coacting paddles.

It will be noted that the movements described, which are inherent in themachine illustrated, are made possible only by correct angular settingof the blades on the two shafts, in relation to each other, the curvedformation of the blades also being required to enable the full effectsof the movements described to take place. With a different relativeangular setting of the blades collision of the same in their rotationswould occur.

Correct angular setting, for the speed ratio chosen for the two shafts,can be readily determined, by experiment or by the preparation ofdiagrams, but definition in terms of definite angular relationships isdiflicult. For example, in the case of the blades F11 and F12, and E11and E12, whose movement was described in detail above, it will be foundthat when the blades of the fast paddle are vertical, the blades of theslower paddle are nearly, but not quite, vertical. this applying to thepaddles as shown, with horizontal shafts and a speed ratio of two toone. The above may not be taken as a relationship true in all cases,however. As to the paddles E21 and F21, as will presently appear, whenthe blades of one paddle are vertical, the blades of the opposing paddlewill be not quite horizontal.

The angular setting referred to will vary with a number of factors fordifferent designs, such as the thickness of the blades, diameters of thehubs, etc. Thus when blade F12 is vertical, blade E11 may be aboutgtendegrees away from vertical, or several degrees on either side of thatfigure. In practice, the angular setting and the curvatures of the frontand rear surfaces of the blades may be determined, after deciding on thematerial and dimensions of the parts, by potting various positions ofthe fast blades and working out, on the drawing board, the angularrelative setting of the slower blades and the curvatures of the bladeswhich will enable, at the various positions, the described movements totake place.

The effect of the angular retardation of the pair of paddles havingblades E21 and E22 with respect to the pair of paddles having blades E11and E12, (or vice versa), is that different phases of the cycle, such asthe squeezing or compression of the material, will occur alternately onthe opposite sides of the machine.

The above will be made clear by further reference to Figs. 3-11,inclusive,in which various positions of the blades E21 and Exam showndotted.

The two blades En and E22 coact with blades F21 and F22, as shown inFig. 2. The blades F21 and F22 are not indicated by reference charactersin Figs. 31 1, inclusive, for the sake of simplicity. Except for thepreferred spiral arrangement of the blades, the blades marked F21 andF22 would be in axial alinement with blades F11 and F12 on the sameshaft, and therefore could not be seen in the views Figs. 3-11. In theabsence of the spiral arrangement, therefore, the blades F22 and F21 maybe considered as represented by blades F11 and F12 in the diagrams ofFigs. 3-11. In that case, as will be seen from the diagrams, the samecycle is followed between blades E21 and E21 and F21, F22 as betweenblades E11, E12, and F11, F12, but with different timing. Thus, forexample, the squeezing of the material between the approximatelyparallel blades E22 and F21 indicated in Fig. 4 (in which blade F21 isrepresented by F111), is the same as the squeezing between blades E11and F11 in the sixth position, Fig. 8, those positions shown in Figs. 4and 8 being separated by one-half a revolution of the fast shaft.

When the spiral arrangement of the blades is used, as shown in Figs. 1and 2, blades F21, at different planes taken at right angles to theiraxis, will, of course, be more or less advanced in their planes ofrotation with respect to corresponding elements of blades F11 and F12.The operation in this case will be explained in the following paragraph.

The feature of the invention as shown, which may be termed the spiraldisposition of the blades on their respective shafts, will now bedescribed. Preferably, as previously stated, each blade is so set on itsshaft that its laterally extending elements are inclined at angles tothe.

axes of the shafts. This is for the purpose of providing the blades withdeflecting surfaces, for

causing the material which isbeing mixed to move axially of the shafts,in addition toits rotating movement. This may be accomplished, as shown,by twisting each blade progressively from its base to its outer edge, inspiral or helical fashion. with the result that each blade will dei'lector move the material in the axial direction as well as rotating it. Theprovision of some means for moving the material axially is highlydesirable, since otherwise some types of material would tend to packbetween the blades of coacting paddles, during compression of thematerial between such blades, probably causing damage.

In the arrangement shown in the drawings all of the blades of thepaddles F on shaft d are given a spiral in the same direction, so as toform one continuous spiral. The blades of two of the paddles on shaft 0form a continuous similar spiral, whereas the blades of the other twopaddles form a continuous spiral which is the same as that of the firsttwo with an interruption of about ninety degrees.

In the construction shown in the drawings, the spiral of the blades onshaft c recedes, while that of the blades on shaft d advances, referencebeing made to Fig. 2 and the fact that the shafts c and d turn towardeach other in that view. With this construction, the full length of theedge of each blade will, or may, wipe closely adjacent to the hubs ofthe coasting paddle, cyclically. Also, wiping action of each bladeagainst the front and rear surfaces of the blades of the coacting paddlewill, or may, take place at the extreme right hand edge of each group ofpaddles referring to Fig. 2 of the drawings.

What I claim is:

1. In a mixing machine, the combination of a container, parallel shaftstherein, alined paddles on said shafts, each comprising a hub portionand a pair of radially extending diametrically opposed blades, means forrotating said shafts in opposite directions with the speedv of rotationof one double that of the other, said shafts being suitably spaced andsaid blades being each of suitable length to cause theirouter edges topass 45 closely adjacent to the hub portionof the opposite paddle, saidblades each being curved, in its direction of rotation, and each paddlebeing so angularly set on its shaft in the plane of rotation as toenable the blades of the faster paddle periodically to overtake and passadjacent to the blades of the slower paddle, without interference.

2. In a mixing machine, the combination of parallel shafts, a pluralityof paddles on each shaft, the paddles of one shaft being alined with thepaddles on the other shaft in pairs, for cooperation, each paddlecomprising a pair of oppositely extending blades, means for rotating theopposed shafts in opposite directions with the speed of rotation of onedouble that of the other, said blades being of suitable lengths to passclosely adjacent to the axial portions of the opposed paddles, eachpaddle being so angularly set on its shaft in the plane of rotation inrelation to the setting of the opposed paddle as to enable the blades ofone paddle of each pair to overtake and pass adjacent to blades of theother paddle of the pair, recurrently, without interference, and theblades of paddles axially separated along one shaft being set atdifferent angles from each other in their respective parallel planes ofrotation.

3. In a mixing machine, the combination of m and pass adjacent to bladesof the opposed paddle, recurrently. without interference, and saidblades being inclined at angles to the axes of said shafts.

4. In a mixing machine, the combination of 5 parallel shafts, aplurality of paddles on each shaft, the paddles of one shaft beingalined with the paddles on the other shaft in pairs, for cooperation,each paddle comprising a pair of oppositely extending blades, and meansfor rotating go the shafts in opposite directions with the speed ofrotation of one double that of the other. said blades being of suitablelengths to pass closely adjacent to the axial portions of the opposedpaddles, each paddle being so angularly set in the plane of its rotationin relation to the setting of the opposed paddle as to enable the bladesof one paddle of each pair to overtake and pass adiacent to blades ofthe other paddle of the pair, recurrently, without interference, andsaid blades 0. being laterally spirally curved, the center line of eachspiral being the axial line of the shaft.

5. In a mixing machine, the combination of a pair of shafts, paddlesthereon alined for cooperation, each comprising a hub and a pair of 35.blades extending radially therefrom, and means for rotating said shaftsin opposite directions with the rate of rotation of one double that ofthe other, said blades being of suitable length to cause their outeredges to pass closely adjacent 0- to the hub portions of the opposedpaddles, and

the blades of the more slowly moving paddle being provided withconcavely-curved surfaces adjacent to which the outer edges of the morerapidly moving paddle may pass, recurrently.

6. In a mixing machine, the combination of parallel shaftsrpaddlesthereon alined for cooperation, each comprising a pair of diametricallyopposed blades extending radially therefrom positioned to rotate insubstantial alinement with w the blades of the paddle on the othershaft, and to intersect deeply the circle described by the 60 of theopposing paddle as to enable blades-of the faster paddle periodically toovertake blades of the slower paddle, approach closely thereto, and thenswing away therefrom, without interference.

1. In a mixing machine, the combination of parallel shafts, paddlesthereon alined for cooperation, each comprising a pair of diametricallyopposed blades extending radially therefrom positioned to rotate insubstantial alinement with m the blades of the paddle on the othershaft, and

to intersect deeply the circle described by the outer edges of theblades of said other paddle, and means for rotating said shafts inopposite directions with the rate of rotation of one double parallelshafts, alined paddles on said shafts, 1 that of the other, said bladesbeing concavely and convexly curved on their forward and rear facesrespectively in their directions of rotation and each paddle beingangularly so set on its shaft in the plane of rotation in relation tothe setting of the opposing paddle as to enable blades of the opposingpaddles periodically to approach each other closely and then swing awayfrom each other without interference, with one blade of the tasterpaddle passing in front of one blade of the slower paddle and thereafterthe other blade of the faster paddle passing behind the same blade ofthe slower paddle in the course of each revolution of the faster paddle.

FRITZ BEKEN.

